This book was written over 50 years ago, so I suppose we must make some allowances for light that has been shed on past events between now and then, but still, there were a number of silly errors in this book which didn't help its credibility: the pre-contract was with Eleanor Butler (nee Talbot) and for some odd reason the book gives her given name as Joan, and Edmund Tudor died of the plague and not in battle.
Overall the book follows a somewhat traditionalist stance, although Henry Tudor comes across as pretty cold and unlikeable. I wasn't convinced by some of the internal logic and some of the characterisation though. Anne Neville, for example. She is a figure we really don't know that much about, but it's hard to conceive she could be as simple and naive as she is portrayed here! Barnes does try it on a bit with trying to make us wonder if 'Perkin' is really Richard of York (and here the historical novelist has licence, because we really don't know!), despite having Bess keep adamantly stating that she knows her brothers are dead. We're also told that Elizabeth Woodville believes they died, which might lead one to question why she would have a finger in a rebellion against her daughter as queen consort? And if everybody really believed this, why did Sir William Stanley lose his head for saying he wouldn't fight against 'Perkin' if he was really a son of Edward IV - and that is in the historical record as well as this novel. There's an awful lot about Bess believing both Richard and Henry have potentially been culpable in acts of murder, but she herself in this novel is guilty of an act of treachery that is at least as bad!
Not a badly written novel, but I found it frustrating overall!